Abstract

Transport measurements were used to characterize . While the carrier concentration,, remained relatively unchanged from 300 down to , the mobility increased from 2100 to over . Shubnikov-de Haas oscillations were observed in fields as low as . Despite the high , quantum Hall plateaus, which are rarely reported in conventional with comparable , were observed. The calculated quantum scattering time of is longer than what is typically reported for conventional . This improvement is believed to be due to a reduction in alloy scattering.

Received 03 October 2006Accepted 15 December 2006Published online 26 January 2007

Acknowledgments:

The authors would like to thank D. Shallenberger for his technical assistance with the SdH system, Patrick Johnson for his help with the Hall data, and Frank Szmulowicz for his many useful discussions. One of the authors (S.E.) was supported in part by an Air Force Summer Faculty Fellowship administered by the American Society for Engineering Education. Parts of this effort were supported separately by the Air Force Office of Scientific Research and DARPA.